The laying of artificial or natural grass for various sporting purposes invariably results in high costs. The result is primarily dependent upon how well the under surface or base has been prepared. For example it is important that the drainage is adequate. In addition the outer layer of sand and gravel must be separated from layers of clay beneath so that these do not migrate upwards and damage the grass layer. There are various types of separation layers for this purpose, for example so called geo-textile which forms a barrier layer between for example clay and macadam.
When laying artificial grass surfaces, for example for football or tennis, the artificial grass is laid upon a drainage rubber matting, so called Dimple Pad. Up until now attempts to lay this matting (artificial grass and Dimple Pad) directly onto a sand/gravel base have been shown to give rise to problems in the form of abrasion damage to the rubber matting. Should this wear become such that holes are created in the matting, this will be clearly noticed because a ball will bounce irregularly. In addition the damage can propagate upwardly into the supporting layer of the artificial grass whereby players can be seriously injured should the studs snag in the damage.
Known geo-textiles have not been able to withstand the stresses which arise in this special area of use. It is thus common that this type of artificial grass is laid on an asphalt base which is, of course considerably more expensive than sand or gravel.